ABSTRACT This proposal is to request support for a Keystone Symposia meeting entitled [unreadable]Cell Death in the Immune System[unreadable], organized by Douglas R. Green and Pam S. Ohashi, which will be held in Breckenridge, Colorado from February 7 [unreadable] 12, 2008. There are two processes in the body in which the life or death of a single cell can profoundly impact on the health of the individual. One is, of course, cancer. The other is the immune response which can be mediated by the progeny of one specific lymphocyte. This meeting will focus on the molecular mechanisms controlling cell death and survival during immune responses, and how these processes affect immune outcome. Topics at the forefront of this field include the regulation of caspases and their control of inflammatory events, the clearance and impact of apoptotic cells and their associated antigens on immune responses, cytotoxic mechanisms including novel granzymes and death receptors, and the role of autophagy in host defense, all to be addressed in this meeting. Joint sessions, with the Keystone Symposium entitled Cell Death and Cellular Senescence, will focus on general mechanisms of apoptosis, including the Bcl-2 family, cellular homeostasis, and signaling events in cell survival.